Electrical connector



ELECTRICAL CONNECTOR Filed Nov. 14, 1942 ATTO RN Patented Aug. 28, 1945ELECTRICAL CONNECTOR Stephen N. Buchanan, Elizabeth, N. J asslgnor toAircraft-Marine Products, Inc., Elizabeth, N. J., a corporation of NewJersey Application November 14, 1942, Serial No. 465,545

9 Claims.

This invention relates to electrical connectors and, more specifically,to a connector plug assembly adapted to connect simultaneously aplurality of electrical conductors in a compact and practical manner orto lead them through a partition, bulkhead, or the like. The inventionalso relates to connector pins for use in such plugs.

There are many instances where a plurality of electrical conductors mustbe connected or brought through a partition, pressure-tight bulkhead, orthe like, within a restricted area. The wiring for an ordinaryinstrument panel and its associated parts is an example. The electicalcontrol apparatus of airplanes and of naval vessels and radio andtelephone circuits afford others. Attempts have been made heretofore toprovide multiple contact plugs for these purposes and plugs directedtoward these ends are now available. In a copending application ofVernon E. Carlson, Serial No. 465,547, filed herewith, there is shown amultiple plug which permits one to insert, remove, or replace individualconnectors in the plug after it is made. Such a structure removes thenecessity for clearances between the individual connectors which arenecessary when one has to solder the electrical conductors to theconnectors while in the plug. This permits more connectors to be crowdedinto a given plug area; but this advantage soon comes to a new limit inthe fact that the individual connectors, where they pass through theplug, have to be spaced from one another sumciently far apart to preventelectrical creepage across the surfaces of the plug from one connectorto another. The spacing necessary in a given plug or socket has dependedupon the current and voltage requirements, the dimensions of theindividual conductors, and the materials used. I

It had been proposed prior to this invention to increase the creepagedistance between adjacent connections. Such structure as was known,however, is of no avail where a locking slide is used, as in saidcopending application of Vernon E. Carlson, since the creepage distancewill always be the minimum distance along the surface of the slide. Thepresent invention gives for the first time a practical multiple plugassembly susceptible of mass production in which the individualconnectors can be spaced more closely than the permitted creepagedistance.

It is an object of this invention to provide an improved multiple pinelectrical connecting means. A further object is the provision of meansfor enabling electrical conductors to be connected in a compact mannerthrough a partition.

A still further object is the provision of improved means for locking aplurality of electrical conductors into a multiple plug or socket.Another object is to provide insulating means in a multiple pin plug orsocket to give a more compact multiple pin connector than has heretoforebeen feasible for a given number of connectors. Other objects will be inpart pointed out as the description proceeds and will in part becomeapparent therefrom.

The invention is made possible through the combination of a plurality ofremovable pins, each adapted to be fastened to an electrical conductor,with a plug adapted for reception of said pins in spaced relation, andwith insulating means by which the pins may be locked into the plug.More particularly, it has been discovered that by forming the lockportions of the pins in insulating sleeves carried on the pins wherethey fit through the plug, the pins can be positioned more compactlythan was possible heretofore because of the increase in the electricalcreepage distance effected by the sleeves. In this respect the inventionis an improvement upon said invention of Vernon E. Carlson, Serial No.465,547, filed herewith.

In this specification and in the accompanying drawing, I have shown anddescribed a preferred embodiment of my invention ad variousmodifications thereof. But it is to be understood that these are notintended to be exhaustive nor limiting of the invention, but, on thecontrary, are given for purposes of illustration in order that othersskilled in the art may fully understand the invention and its principlesand the manner of applying it in practical use so that they may modifyand adapt it in various forms, each as may be best suited to theconditions of a particular use.

In the drawing, in which like reference characters refer to like partsthroughout and in which exemplary embodiments for attaining the aboveobjectives are set forth:

Figure 1 is an enlarged perspective view of one type of connector plugembodying the invention;

Figure 2 is a plan view of the locking means used in the plugillustrated in Figure 1.

Figure 3 is a longitudinal elevation, partially in section, of aterminal pin of the type used with the plug illustrated in Figure 1;

Figure 4 is a perspective view of an eccentric used in the plugillustrated in Figure 1;

ure 5 is a sectional view taken through a plug similar to that shown inFigure 1 but show- 9 ing a modification thereof;

Figure 8 is a sectional view similar to that of Figure 5 showing anadditional modification; and Figure '7 is a sectional view similar tothat of Figure 6 showing a further modification. 7 Referring to Figure1, a plug indicated generally by 40 is illustrated. For a more completeshowing of one of the manners of using a plug of this type referencemaybe had to the aforementioned application of Vernon E. Carlson or theapplication of Harry B. White, Serial No. 465,546, filed herewith. Plug40 comprises socket plate 4i, socket plate 42, and a locking means 48therebetween. In the present embodiment locking means 48 consists of aninsulating plate, illustrated in greater detail in Figure 2, whichengages in grooved insulating sleeves 54 on the contact pin 44 (Figure3).

Plates 4i, 42, and 45 may be made of Bakelite or other phenolic resin,vulcanized fiber or other insulating material. Plates 4| and 42 are heldin assembled relationship by clamping means 43 comprising in the present,embodiment a conventional rivet construction; Locking plate 48 isslidably mounted between plates 4| and 42, in this instance beingrotatable about a bearing rivet 41 fitted through a bearing hole 55 inplate 48 (see Figure 2). Plate 481s provided with arm ate slots 50through which rivets 48 extend and which allow for rotation of plate 48about bear ing 41 and with respect to plates 4| and 42.

Plate 48 may be moved with respect to plates 4| and 42 by any suitablemeansyjadvantageously in the case illustrated by means of an eccentric49 (see ,Flgure 4). Eccentric 49 is threaded into and rotatable in plate42, and the eccentric portion is received in a radial slot 52 of plate48. The end of the eccentric i provided with a kerf for reception of ascrew driver blade bywhich it may be turned to rotate the locking plate.Socket plates 4| and 42 carry aligned openings 54 adapted to receivepins 44 (Figure 3), as indicated in Figure 1. Also in alignment withopenlugs 55 are keyhole slots 5| in plate 48.

As plate 48 is rotated with respect to plates 41 and 42, the keyholeslots 5i are moved with respect to openings 55. In one extreme positionof eccentric 45, the larger portions of keyhole slots 5i are inalignment with openings 58 and in the other extreme position of theeccentric the smaller portions of the keyhole slots are coaxial with theopenings 58.

Instead of a rotary locking plate, this plate may beslidable laterallywith respect to'the socket plates and in such case, a part of thelocking plate may advantageously roject beyond the socket plates in theopen position so that the plug cannot be inserted into a receptacleuntil the contact pins are locked in place by sliding the locking plateto locking position. Such a plug is shown in Figure 5 where, in theposition shown, the pins 44a are locked within plug 4011. Plate 48:: isarranged to be moved vertically, as shown in Figure 5, to release thepins from the socket plates. I

Figure 3 illustrates one of the terminal connectors or pins 44. Pin 44is provided with a ferrule and 45, a lock portion and a contact end, 48.Ferrule end 45 is in this case of a type used in making a solderlessconnection with an electrical conductor. Usually such a connection ismade by a crimping operation. In the broadest aspect of the presentinvention the connection might be soldered or brazed or connected in anyother manner known for connecting conductors to terminals. Lock portion55 comprises a assaooe sleeve 54 which covers the central portion of thepin and whichwili be described in more detail hereinafter. Contact end46 is proportioned to extend through the plug and may be either male offemale, depending upon the installation at hand.

Sleeve 54 consists of an insulating material, such as Bakelite, andpreferably is permanently molded or cemented or shrunk in place along.the central portion of the pin. This central portion is shown ofreduced diameter to assist in holding the sleeve securely in its properposition; knurling or other surface treatment may be used likewise toanchor the sleeve to the pin. These expedients, however, are notessential.

This sleeve is somewhat longer than the width of the plug with which itis to be used and its length is so related to the groove 55 that, when apin is locked in position in the plug, the insulating sleeve wil1project on either side of the plug beyond the faces thereof, asillustrated in Figures 1 and 5. By this arrangement the creepagedistance is no longer the distance between the pins 44 on the surface orthe plates 4| or 42 nor on the surface of the locking slide 48, .butinstead is the sum of the spacing on the surface of the plates plus thedistances to the ends of the sleeves 54 plus the thicknesses of thesleeves. Since sleeves 54 also carry the circular grooves 55 which formthe lock portions for the connector pins, the pins are fully insulatedagainstdirect creepage along the surface of the locking slide plate 48.

Although I have used the sleeves 54 to increase the creepage distanceboth at the outer surfaces of plates 4| and 42 and at the inner facesbetween these and the locking plate 48, only the latter/is necessary andif it is desired, the outer surfaces may be treated with annularcorrugations or otherwise as previously known for simple molded plugs.Also it will be understood that my invention may be utilized at thesesurfaces by terminating the sleeves 54 short of the outer surfaces ofplates 4| and 42 instead of extending them beyond said surfaces, andkeeping the opening of larger diameters, beyond the end of the sleeves,than the corresponding portions of the pin, so that there can be nodirect creepage between pins over the outer surfaces of the plates.Figures 6 and 7 illustrate examples of such arrangements.

Hence, the insulating sleeves at the same time serve both to lock thepins in the socket and to increase the creepage distances between thepins. The advantages of this double function are twofold. The lockingfeature allows the pins to be permanently attached to the electricalconnectors under ideal working conditions before being assembled throughthe plug. Thus, no space need be provided at the plug to allow formaking soldered or crimped connections. At the same time the increasedcreepage distance afforded by the sleeves allows full advantage to betaken of the compact assembly enabled by the locking feature withoutdanger of electrical breakdown from short circuits or current lossesbetween adjacent pins.

It will be understood, of course, that the showing of only two or threepins in the drawing and the exaggeration of dimensions of the sleeve 54and groove 45 and of various other parts are for clearer illustration.In practice the pins may circumferentially grooved insulatin of thesleeve of the pin lating material is used and high voltages are not tobe encountered.

Thus, the invention provides in a practical manner for electricalconductors to be connected through a partition permanently, tightly, andcompactly without the limitations inherent in earlier connections knownin the prior art.

As various modifications and changes might be made in the invention asset forth, and as different designs thereof will be necessitated by themany applications to which it may be put, patent protection is notintended to be limited to the embodiments described and illustrated. Thescope of the invention on the contrary is intended to be limited solelyby the accompanying claims.

I claim:

1. In an electrical connection of the type having a plug and a contactpin therefor and means operable within the plug for locking the pin inthe plug; an insulating sleeve surrounding said pin and extending ateach end thereof to a position substantially spaced from the plane ofany transverse surface of said plug and having a lock portion, and saidplug including an opening fitted to said pin and having a locking meansto engage the lock portion of the sleeve of the pin in the opening,whereby said pin may be locked in said plug when it is inserted into theopening.

2. In an electrical connection, a plug and a contact pin therefor; saidpin including an insulating sleeve having a lock portion and said plugincluding an opening fitted to said pin and having a locking means toengage the lock portion in the opening, whereby said pin may be lockedin said plug when it is inserted into the opening; the length of saidsleeve on each side of said lock portion being other than the distancefrom said locking means to the surface of any lamina of said plug,whereby the creepage distance between said pin and any other pin whichmay be in said plug is increased over the spacing distance between saidpin and said other pin. 1

3. In an electrical connection, a contact pin and a plug including aninsulating support; said pin including a ferrule end, a contact end, andan intermediate insulated lock portion havinginsulation extending beyondthelock portion on each side thereof along the pin and terminating inoffset relationship with respect to any transverse surface of the plug,and said insulating support including an opening fitted to said pin andhaving locking means associated with said opening, whereby the pin maybe inserted into the support after its ferrule has been secured to anelectrical conductor and thereafter locked in assembled relationshipwith the ferrule end on one side of the insulating support and thecontact end projecting on the other.

4; The combination with a multiple pin type plug having, a plurality ofpin type terminal conan electrical conductor before being positioned inthe receptacle and thereafter may be locked in the receptacle inclosejuxtaposition adjacent one another with creepage distances greater thantheir spacings.

5. In an electrical connection, a plug and a contactpin therefor; saidpin including an insulating sleeve having a lock portion and said plugincluding an opening fitted to said pin and having a locking means inthe plug to engage the lock portion of the sleeve of the pin in theopening, whereby said pin maybe locked in said plug when it is insertedinto'the opening, said insulating sleeve being of such length that theend faces oi. said sleeve do not coincide with the faces of said plug,whereby the creepage distance between said pin and any other pin in saidplug is increased over the straight line distance between said pins.

6. In an electrical connection, a plug and a contact pin therefor; saidpin including an insulating sleeve having a recessed lock portion andsaid plug including an opening fitted to said pin and a slidable plateintercepting said opening and adapted in one position thereof to projectinto said opening to engage in the recessed lock portion of said sleeve,whereby it may be locked in assembled relationship, and in anotherposition to be withdrawn from said opening to permit insertion andremoval of said pin, said insulating sleeve being of such length thatthe end faces of said sleeve do not coincide with either the outersurfaces of the faces of said plug or the faces of said slidable plate,whereby the creepage distance between said pin and any other pin in saidplug is increased over the straight line distance between said pin andsaid other pin.

7. The invention of claim 5 wherein the end faces of said sleeve extendbeyond the faces of said plug.

8. The invention of claim 5 wherein the end faces of said sleeve arecountersunk with respect to the faces of said plug.

9. The invention of claim 5 wherein one of the end faces of said sleeveextends beyond the adjacent face of said plug and the other end face ofsaid sleeve is countersunk with respect to its adjacent face of saidplug.

STEPHEN N. BUCHANAN.

